Is it possible to filter the fields returned in a solr Document?

Question

I have solr documents that look like this:

<doc>
    <str name="some_attribute">some_attribute_value</str>
    <!-- ... -->
    <arr name="locationCoordinates">
      <str>48.117,11.539</str>
      <str>23.423,11.342</str>
      <!-- ... -->
    </arr>
</doc>

My question is whether it's possible to filter the returned fields of a document to only return certain values, for example to only return the locationCoordinates that are within a 50 km range of another point and leave the others out.

I.e. return the above document, but with only the first locationCoordinates.

I don't really know whether this should even be possible in Solr (because of the document-oriented structure), but I can at least ask :).

Maybe I should also elaborate on the way I want to use this feature and alternatives I "found" for this:

change the document design to create one document per location (Pro: works, Cons: need to check for duplicates on the client side, heaps of duplicated data in the Solr-database)
leave it with this structure (Pro: works, don't have to change the current structure, Cons: I have to sort the correct coordinates out by myself (on the client) and therefore encounter problems with distance calculation (I already filter the documents by distance beforehand, and maybe I will lose some data if I compute the distance on the client-side badly)
create a new Document "type" for the locations (and their names, etc.) on the Solr-side and use a foreign-key-like structure to add the locations to the articles and in order to compute distances I have to query for reachable locations first and then join on the articles (Pro: everything works on the solr-side, Cons: I will need Solr-Joins for that)

Answer probably found on this question: stackoverflow.com/questions/14015696/… But how can I achieve the behaviour mentioned above? — Martin Braun

Mavellin Mavellin · Accepted Answer · 2013-03-25T10:58:14

change the document design to create one document per location (Pro: works, Cons: need to check for duplicates on the client side, heaps of duplicated data in the Solr-database)

If this is your only concern, probably you can consider making the locationCoordinates as your unique_key for each document.

By doing this, you are not allowing duplicate locationCoordinates in your Index, thereby eliminating the need to check for duplicates on the client side.

Is it possible to filter the fields returned in a solr Document?

1 Answers